DAEGU, South Korea — Even with the 200 meters already won, Usain Bolt gritted his teeth and dipped his 6-foot-5 frame at the line.

He proved his point.

The Jamaican may have clowned around before the race and renewed his antics afterward, but for 19.40 seconds Saturday at the world championships, he was as all business. And when he's this serious, he's impossible to catch.

"I am still the best," he said. "It was beautiful."

Bolt stayed an instant longer in the starting blocks, clearly not wanting to false start as he did in the 100 final when he was disqualified. His slow start hardly mattered. He quickly passed the competition around the curve. From there, it was simply a matter of what his time would be. He didn't let up, huffing and puffing all the way.

It wasn't near his world record of 19.19, but it was the fourth fastest in history. And that's with Bolt admitting he's nowhere near his record form of two years ago at the worlds. He expects that to change for next year's London Games, when the stakes are bigger and the lights brighter.

"I have to come to the Olympics and do my extreme best and blow the peoples' minds," Bolt said.

On Saturday, he was not the entire show. The Americans hauled in five medals to increase their total to 21, four more than Russia.

Allyson Felix and Sanya Richards-Ross led the women's 1,600-meter team to gold, while Walter Dix wound up with silver, finishing 0.30 seconds behind Bolt. Danielle Carruthers and Dawn Harper couldn't catch Sally Pearson in the 100 hurdles but still took silver and bronze.

The surprise of the night for the U.S. came when 21-year-old Matthew Centrowitz finished third in the 1,500 meters, less than a second behind winner Asbel Kiprop of Kenya.

"(She) made me think it was possible," said Centrowitz, whose father was a two-time Olympian. "She set the tone."

In other finals, Sergey Bakulin of Russia won the 50-kilometer walk, Matthias De Zordo of Germany took the javelin title and Anna Chicherova of Russia beat two-time defending champion Blanka Vlasic of Croatia in the high jump.

But on this night, as on so many, Bolt was the headliner.

Like a maestro, he performs to his adoring audience. Bolt drew applause simply for stepping into the stadium, more for bumping fists with a track attendant and even more for his signature bow-and-arrow pose.

And this was the warmup act. In the main event, he was simply dazzling.

So in control was Bolt, he could have let up with a few strides of his long legs left — something he's done countless times — but he was out to make a point: He's still the same unbeatable Bolt.

"He ran great," said Dix, who also won silver in the 100.

These days, Bolt is so entertaining other athletes stop what they're doing to catch a glimpse. Felix stood on a step beneath the stadium and gazed out at the scoreboard.

"You're always wondering, 'What is he going to do? What is he going to run?'" Felix said. "He always puts on a good show."

Felix and her relay teammates weren't too bad themselves.

Richards-Ross, who typically runs the anchor leg, wanted to go first, just to get the squad a lead. She did and handed off to Felix, who extended the lead and looked not the least fatigued as she took the track for her seventh race of the championships.

For Felix, this was her seventh gold over four world championships. She has a chance for more, planning to run in the 400 relay Sunday.

"Sanya made it easy on us," Felix said.

In the hurdles, Pearson ran the fastest race in almost two decades to take the title. Carruthers and Harper finished so close it took a while to determine Carruthers was the silver medalist.

To even be in this position was a shock to Harper. A year ago, her career was in jeopardy after a routine procedure to repair a ligament in her right knee revealed more significant damage.

"They found extra stuff under my kneecap and said I may never hurdle again," said Harper, the 2008 Olympic gold medalist. "To come back and be in this moment is such a blessing. That race was intense."

Kellie Wells entered the worlds with one of the fastest times of the season, but stumbled over a hurdle and tumbled. Unable to finish, she limped off the track.

The most astonishing performance for the Americans came from Centrowitz, who moved to the outside down the home stretch and found another gear to become the youngest American to earn a medal.

"Taking that victory lap I didn't think it was real," he said. "Everybody believed in me and finally I started to believe, too."